Early Coronary Angioplasty Research Articles

Serial changes in atrial and brain natriuretic peptides in patients with acute myocardial infarction treated with early coronary angioplasty

To examine the role of brain natriuretic peptide (BNP) in acute myocardial infarction (AMI), we measured the plasma concentration of immunoreactive (ir) BNP together with that of atrial natriuretic peptide (ANP) over the 4-week course of AMI in 16 patients treated with early coronary angioplasty. Both the plasma ir-ANP and ir-BNP levels were increased on the first day of the infarction compared with the values in normal subjects. During the clinical course of the infarction, the plasma ir-ANP concentration soon decreased, while the plasma ir-BNP level remained elevated at 2 weeks after the infarction, also exhibiting a high level at 4 weeks. Plasma ir-BNP levels on day 1 or days 14 and 28 were inversely correlated with left ventricular ejection fraction obtained by left ventriculography at the acute or chronic phase, respectively. Plasma ir-BNP concentrations on days 14 and 28 were positively correlated with the maximal myosin light chain I level, an indicator of infarct size. These observations suggest that the plasma ir-BNP level increased to compensate for the ventricular dysfunction associated with the size of the infarct in AMI. BNP may act as a cardiac hormone in AMI, differing somewhat from ANP in its synthetic, secretory, or clearance behavior.

Antithrombotic therapy in left ventricular thrombosis and systemic embolism

Left ventricular (LV) thrombi are responsible for significant morbidity and mortality in our society. Twenty-five percent of cardiogenic emboli are associated with acute and chronic myocardial infarction. With the development of noninvasive imaging techniques LV thrombi have been increasingly recognized as an important clinical entity; the imaging method of choice is two-dimensional echocardiography. LV mural thrombi occur in one third of Q wave anterior myocardial infarctions; their occurrence in patients with non-Q wave infarction and inferior Q wave myocardial infarction is less than 5%. More than half of all LV thrombi are formed within 48 hours of acute myocardial infarction, and nearly all thrombi have been formed within a week of infarction. The development of an LV thrombus is associated with some risk of systemic embolization. To prevent LV thrombosis and systemic embolism, full-dose heparin followed by warfarin therapy for at least 3 months is indicated for patients with large anterior infarctions and those with heart failure. The use of thrombolytic therapy does not reduce the risk of LV thrombus formation; few data exist on whether early coronary angioplasty reduces the risk of LV thrombus formation and the risk of embolization. The proper treatment for patients with chronic LV thrombi remains unknown.

Critically ischemic myocardium in clinically stable patients following thrombolytic therapy for acute myocardial infarction: Potential implications for early coronary angioplasty in selected patients

The utility of post-thombolysis, rest-redistribution thallium (TI)-201 scintigraphy was studied in 32 patients with a first myocardial infarction who were clinically stable following reperfusion. Day 1 scintigraphy obtained 5 ± 4 hours (range 1 to 16) after thrombolysis revealed an average perfusion defect of 6.5 ± 2.6 segments (range 1 to 11). There was a total of 208 abnormal segments, 137 of which were nonreversible at 4 hours, 50 of which were fully or partially reversible, and 21 of which had a reverse redistribution pattern. Repeat TI-201 scintigraphy on day 10 revealed significantly smaller perfusion defects of 4.9 ± 2.4 segments (range 0 to 9) with improvement predominantly of the day 1 reversible segments, and the improvement in segmental perfusion correlated with better regional left ventricular function. Twenty-nine (58%) of the 50 reversible segments normalized by day 10, and 11 (22%) improved, whereas only 16 (12%) of 137 nonreversible segments had normalized by day 10, only 9 had (6%) improved and 112 (82%) were unchanged ( p < 0.001 reversible versus nonreversible). There was no significant change in segments with a pattern of reverse redistribution. The improvement of reversible segments was greater in the 16 patients who underwent coronary angioplasty (PTCA) during the interval between the two scintigrams than in the 16 who did not. All 24 reversible segments in the PTCA group improved or normalized by day 10 compared with 16 (62%) of 26 reversible segments in the No PTCA group ( p < 0.001). Furthermore, 8 of the 10 reversible segments in the No PTCA group that did not improve actually deteriorated and became nonreversible by day 10. The minor improvement of nonreversible segments was not related to PTCA. Consistent with the findings in individual segments, the 19 patients with a reversible component on the day 1 TI-201 scintigram had significantly greater improvement in perfusion defect by day 10 than the 13 patients without a reversible component (37 ± 33% versus 7 ± 22% decrease in perfusion defect severity, p < 0.05), and this improvement was greatest in the 10 patients with a reversible component who underwent PTCA. In contrast, PTCA had no impact on the perfusion defect in the 13 patients without a reversible component. Our data suggest that following thrombolytic therapy for acute myocardial infarction, viable myocardium in the reperfused zone may remain ischemic, as manifested by a reversible pattern of TI-201 redistribution at rest, and thus may be in jeopardy of gradual progression to necrosis. Since PTCA appeared to prevent necrosis in these “critically ischemic” or “moribund” myocardial segments, out findings may have implications for the early recognition of a subgroup of patients who may benefit from post-thrombolysis PTCA of the residual stenosis of the artery of infarction.

A Randomized Trial of Intravenous Streptokinase Versus Tissue Plasminogen Activator for the Treatment of Acute Myocardial Infarction: Results Using an Aggressive Approach

Seventy‐six patients presenting within 6 hours of the onset of an acute myocardial infarction were randomized to either treatment with 1.5 million units of Streptokinase or 100 mg of recombinant tissue plasminogen activator intravenously. Patients not demonstrating clinical reperfusion within 1 hour were taken emergently for “salvage” angioplasty or coronary bypass surgery. Those patients demonstrating clinical reperfusion underwent early (12 to 72 hours) elective angiography and either elective angioplasty or bypass surgery. The mean time from pain onset to treatment was 149 minutes in the Streptokinase group and 134 minutes in the recombinant tissue plasminogen activator group (P = NS). There were no statistical differences between groups with regard to prior myocardial infarction, infarct location, prior coronary bypass surgery and Killip classification. Clinical reperfusion was demonstrated in 56% of the Streptokinase group and 53% of the recombinant tissue plasminogen activator group (P ‐ NS). Angiographic patency was demonstrated in 70% of the Streptokinase group and 66% of the recombinant tissue plasminogen activator group (P = NS). Left ventricular ejection fraction at discharge was no different: 47% in the Streptokinase group and 43% in the recombinant tissue plasminogen activator group (P = NS). Recurrent ischemic events were found more often in the recombinant tissue plasminogen activator group, 18%, versus the Streptokinase group 3% (P = 0.05). Treatment outcomes did not differ between groups. There was one (3%) death in the Streptokinase group versus two (6%) deaths in the recombinant tissue plasminogen activator group (P = NS). There was a trend toward a greater need for emergent coronary bypass surgery after attempted angioplasty in the recombinant tissue plasminogen activator group, four of 18 patients (22%) versus one of 23 patients (4%) in the Streptokinase group (P = 0.14). In summary, in the setting of acute myocardial infarction treated by thrombolysis, those patients treated with recombinant tissue plasminogen activator experienced significantly more recurrent ischemic events and required emergent coronary bypass surgery more frequently for failed angioplasty compared to those treated with Streptokinase. The results suggest there may be agent specific increases in complications dependent upon the thrombolytic agent of choice when salvage or early coronary angioplasty is used.

Acute myocardial infarction treated with intracoronary streptokinase: A report of the society for cardiac angiography

The Society for Cardiac Angiography maintains a registry of intracoronary streptokinase therapy (IC-SK) in patients with acute myocardial infarction. Between July 1981 and August 1984, 1,029 patients were entered into the registry. The baseline and clinical characteristics of patients were determined, the early results of therapy were evaluated, and baseline characteristics of those in whom reperfusion was achieved were compared with those in whom it was not. Multivariate discriminant analysis was used to identify the predictors of reperfusion and hospital mortality. The overall rate of reperfusion was 71.2%. Reperfusion was positively associated with hypotension, absence of cardiogenic shock and early treatment. The hospital mortality rate for all patients was 8.2% and was higher for women and the elderly. The hospital mortality was significantly lower among patients in whom reperfusion was achieved compared with those in whom it was not (5.5% vs 14.7%, p < 0.0001) and for several high-risk subgroups. Thus, coronary artery reperfusion induced by IC-SK significantly reduces hospital mortality in high-risk patients with acute myocardial infarction. High-risk patients in whom reperfusion fails with IC-SK therapy should be considered for early coronary angioplasty or coronary artery bypass surgery.

Percutaneous perfusion of occluded coronary arteries with blood from the femoral artery: a dog study.

The idea of perfusing the distal coronary artery with arterial blood during balloon dilatation was implemented in early experimental coronary angioplasty but then abandoned. We pursued this concept in an animal model using a specially designed roller pump. The pump delivers blood from a femoral artery catheter through the central lumen of a balloon catheter occluding a coronary artery. Perfusion of large proximally occluded coronary arteries for at least 60 min was possible in 8 of 11 heparinized dogs. Hemolysis occurring in the pump system due to the small catheter lumen proved a minor problem. For a limited period of time, occluded coronary arteries can be adequately perfused with arterial blood by this percutaneous system that is readily applicable in any catheterization laboratory. Its use is conceivable not only for temporary treatment of acute complications during angioplasty but also for prolonged balloon dilatations of spastic or thrombosed coronary arteries.